Computer Architecture vs. Organization Quiz

Computer Architecture vs. Computer Organization

• The importance of understanding the difference lies in how a computer manufacturer can offer a family of computer models with the same architecture but different organization.
• Models in a family can have different price and performance characteristics.
• An architecture can span many years and encompass different models with their organization changing with technology.
• This is demonstrated by the IBM System/370 architecture which was introduced in 1970.
• It included several models with different price points and allowed customers to upgrade to faster models without losing their software investments.

Structure and Function of a Computer

• A computer is a complex system made up of millions of electronic components.
• Computers perform at least two functions: short-term data storage and long-term data storage.
• Short-term data storage happens when the computer processes data and stores it temporarily.
• Long-term data storage is achieved through files stored on the computer for retrieval and update.
• Data movement happens between the computer and its external environment, referred to as input-output (I/O).
• Peripherals are devices directly connected to the computer and act as sources or destinations for data.
• Data communications involve transferring data over longer distances, to or from remote devices.
• Control unit manages the computer's resources and orchestrates the functional parts in response to instructions.

Hierarchical View of a Single-Processor Computer

• A traditional single-processor computer has four main components: central processing unit (CPU), main memory, I/O, and system interconnection.
• The CPU controls the operation of the computer and performs the processing of data.
• Main memory stores data.
• I/O moves data between the computer and its external environment.
• System interconnection, often a system bus, enables communication between the CPU, main memory, and I/O.

CPU Components

• The CPU has three main structural components: control unit, arithmetic and logic unit (ALU), and registers.
• The control unit manages the CPU's operation, including the computer's overall operation.
• The ALU performs the computer's data processing functions.
• Registers provide temporary storage internal to the CPU.
• Communication between the control unit, ALU, and registers is facilitated by the CPU interconnection.

Registers

• The CPU has a high-speed, internal memory with registers for storing temporary results and control information.
• Each register has a defined size and function.
• Registers typically have the same size, capable of holding one number.
• Registers can be read and written at high speed due to their proximity to the CPU.

Hierarchical Structure of a Multicore Computer

• Multicore computers have multiple processors, typically two to ten, forming layers interconnected by copper pathways engraved on the motherboard.
• Chips, single pieces of semiconductor material, often silicon, contain electronic circuits and logic gates.
• The chips are referred to as integrated circuits.

Structure of a Core - Functional Elements

• A core has several functional elements: instruction logic, arithmetic and logic unit (ALU), load/store logic, and caches.
• Instruction logic fetches and decodes instructions, determines the operation, and identifies the memory locations of operands.
• The ALU performs the operation specified by an instruction.
• Load/store logic manages the transfer of data to and from main memory via cache.
• Cache systems have multiple levels: L1, L2, and L3.
• L1 Cache includes a data cache for operand and result transfer and an instruction cache for managing instruction transfer between main memory and the core.
• L2 Cache is often incorporated into the core in modern processor chips.

IAS Computer - AC and MQ Registers

• The IAS computer uses AC and MQ registers for storing the result of multiplication.
• AC stores the most significant 40 bits of an 80-bit result.
• MQ stores the least significant 40 bits of an 80-bit result.

IAS Computer - Operation and Instruction Cycle

• The IAS operates by repeating an instruction cycle which includes two subcycles: the fetch cycle and the execute cycle.
• In the fetch cycle, the opcode of the next instruction is loaded into the IR.
• The address portion is loaded into the MAR.
• The Instruction Register (IR) contains the 8-bit opcode instruction being executed.
• The Memory Address Register (MAR) specifies the address in memory of the word to be written or read to/from the memory.
• The instruction can be taken from the IBR or obtained from memory.
• The execute cycle is performed after the opcode is loaded into the IR.
• Control circuits interpret the opcode and execute the instruction by sending out control signals to move data or perform an ALU operation.

Test your understanding of computer architecture and organization. This quiz delves into how various models from the same architecture can differ in organization, price, and performance, as well as the basic structure and function of a computer system.